JIT: Remove VisitLoopBlocksLexical utility (#110490)

Follow-up to #110227. In the few places where we still visit loop blocks in lexical order, just visit them in RPO instead.

Author: amanasifkhalid

src/coreclr/jit/compiler.h

@@ -2219,9 +2219,6 @@ class FlowGraphNaturalLoop
     template<typename TFunc>
     BasicBlockVisit VisitLoopBlocks(TFunc func);
 
-    template<typename TFunc>
-    BasicBlockVisit VisitLoopBlocksLexical(TFunc func);
-
     template<typename TFunc>
     BasicBlockVisit VisitRegularExitBlocks(TFunc func);
 

src/coreclr/jit/compiler.hpp

@@ -5127,41 +5127,6 @@ BasicBlockVisit FlowGraphNaturalLoop::VisitLoopBlocks(TFunc func)
     return VisitLoopBlocksReversePostOrder(func);
 }
 
-//------------------------------------------------------------------------------
-// FlowGraphNaturalLoop::VisitLoopBlocksLexical: Visit the loop's blocks in
-// lexical order.
-//
-// Type parameters:
-//   TFunc - Callback functor type
-//
-// Arguments:
-//   func - Callback functor that takes a BasicBlock* and returns a
-//   BasicBlockVisit.
-//
-// Returns:
-//    BasicBlockVisit that indicated whether the visit was aborted by the
-//    callback or whether all blocks were visited.
-//
-template <typename TFunc>
-BasicBlockVisit FlowGraphNaturalLoop::VisitLoopBlocksLexical(TFunc func)
-{
-    BasicBlock* const top    = GetLexicallyTopMostBlock();
-    BasicBlock* const bottom = GetLexicallyBottomMostBlock();
-
-    for (BasicBlock* const block : m_dfsTree->GetCompiler()->Blocks(top, bottom))
-    {
-        if (ContainsBlock(block))
-        {
-            if (func(block) == BasicBlockVisit::Abort)
-            {
-                return BasicBlockVisit::Abort;
-            }
-        }
-    }
-
-    return BasicBlockVisit::Continue;
-}
-
 //------------------------------------------------------------------------------
 // FlowGraphNaturalLoop::VisitRegularExitBlocks: Visit non-handler blocks that
 // are outside the loop but that may have regular predecessors inside the loop.

src/coreclr/jit/flowgraph.cpp

@@ -6001,9 +6001,7 @@ void FlowGraphNaturalLoop::Duplicate(BasicBlock** insertAfter, BlockToBlockMap*
 
     Compiler* comp = m_dfsTree->GetCompiler();
 
-    BasicBlock* bottom = GetLexicallyBottomMostBlock();
-
-    VisitLoopBlocksLexical([=](BasicBlock* blk) {
+    VisitLoopBlocks([=](BasicBlock* blk) {
         // Initialize newBlk as BBJ_ALWAYS without jump target, and fix up jump target later
         // with BasicBlock::CopyTarget().
         BasicBlock* newBlk = comp->fgNewBBafter(BBJ_ALWAYS, *insertAfter, /*extendRegion*/ true);
@@ -6213,7 +6211,7 @@ void FlowGraphNaturalLoop::DuplicateWithEH(BasicBlock** insertAfter, BlockToBloc
     BitVecTraits traits(comp->compBasicBlockID, comp);
     BitVec       visited(BitVecOps::MakeEmpty(&traits));
 
-    VisitLoopBlocksLexical([=, &traits, &visited, &clonedTry, &ehIndexShift](BasicBlock* blk) {
+    VisitLoopBlocks([=, &traits, &visited, &clonedTry, &ehIndexShift](BasicBlock* blk) {
         // Try cloning may have already handled this block
         //
         if (BitVecOps::IsMember(&traits, visited, blk->bbID))